Anode



J. S. THELEN 'ANODE Filed July so; 1928 \NVEN'WE mm a. mum

Patented Nov. 8, 1932 JAMEs s. trIIELEII, or CHICAGO, ILLINOIS, ASSIGNOR T GENER L nLEoraIc xnnvoonroRArIoN, or CHICAGO, ILLINOIS, A CORPORATION or new YonK Anonn' AppIication filed J l 30,

The present invention relates to X-ray tubes, or to other tubes in which there is an anode which may, during operation, become heated, and has particuarly todo with the construction thereof and the provision of a mersed X-ray tube as novel means for such anode;

' Included in the objects of the invention are the following provisions:

A'novel and unique means for coolingthe anode of an X-ray tube; f

A new means for constructing the anode of an X-ray tube; I f

Means for grounding the anode ofan oilimmersed tube or the like;

An oil-immersed tube in which the anode is grounded to the tank containing such tube and its energizing equipment;

jThe employment of a'tank for an oil-ima means for absorbing theheat from the anode of a tube and for a radiating such heat to the atmosphere;

The provision of additional means in such a structure for the absorption of heat; and

Removable and replaceable heat-absorbing parts in connection with an anode for an X- ray tube. These, and such other objects as may hereinafter appear, are obtained by the novel construction, arrangement, and combination of elements disclosed in the accompanying dissipating the heat from drawing illustrative of one embodiment of the invention, which embodiment is illustrated in a singlesheet of drawing accompanying this application and hereby made a part hereof, and in which Figure l is a diagrammatic view showing the circuit and the apparatus, the tube and tank both of which are in section;

Figure2 is an enlarged view of an anode for a tube made in accordance with the invention;

Figure 8 is a section along the line 3-3 of Figure 2. V r

One of the great ditficulties encountered in X-ray tube operation because of the tremendous heat produced thereby is the dissipation of such heat. This comprises a problem which annoys all X-ray engineers. The question'of whether the power input toX-ray 1928. Serial No. 296,357,

tubes can be increased and the field of utility.

of X-ray equipment thereby widened de pends in a great measure on how successfully this problemcan be solved.- With the intro-, duction of the oil-immersed type of tube, the importance of this problem has been increased and as is herein indicated, one of the objects of the invention is to provide a structure for this type of X-ray tubes which will facilitate heat-absorption. V

In carrying out the invention, and, in the illustrationthereof, an oil-immersed typeiof tube is described and shown, but of course the invention is not limited to such type of tube. or to X ray tubes. j

.One of the primary considerations for the use of the present invention is the grounding of the. anode of the X-ray tube to the tank in which the X-ray tube and its energizing equipment is enclosed. -By" so doing, it becomes feasible to further use the tank, which is generally "of aluminum or of such similar material of high heat conductivity for a means of absorbing heat from the anodeof the tube and for radiating this heat rapidly to the atmosphere.

In addition to providing means whereby V the'tank assists in the absorption of heat, the anode ofthe tube is of a'particular type comprising a removable section which maybe replaced from time to time, which passes into the shanlrof the anode'may be absorbed by a mass of heat-absorbing material at the outer end of the shank of such anode. I

In this fashion, a tube which has already been heated to the limit, may be very rapidly cooled by the removal of the heated heatabsorbing section of the anode thereof and the replacement of such section with one the temperature of which is lower than that of the anode. It is therefore possible to quickly reduce the temperature of the anode of a tube ifthe use of the machine is necessary subsequent to the time the anode thereof has been run until nearly to the point of maximum allowable temperature.

Like reference characters are used to designate similar parts in the drawing and in the so that the heat A source of power 23 is 3 1, one of these description of the invention which is herein ma e.

A tank 10 for enclosing an X-ray tube and its energizing elements is shown. This is generally made of aluminum or of other material of high-heat conductivity.

Said tank 10 has a cover 11 which has a window for the passage of X-light. Within the tank 10 is the tube 12, the anoaeor which is of special construction to be referred to shortly.

the tube is marked 14. The bulbous portion of the tube 12 is designated 15, and at the end of the anode13, is a laterally extending threaded stud 16 on one of the walls of the tank 10 for the purpose of engaging the threaded end of the anode 13 and supporting the X-ray tube 12in position within the tank 10." The anode 13, as shown, has a hollow stud, the hollow portion being designated 17.

Upon the walls of the tank 10'is a socket 18, the opening in which registers with the opening in the threaded stud 16. and in this socket is a replaceable heat-absorber unit 19 which is adapted to be screwed into position therein tocooperate with the anode 13, filling the hollow portion 17 of the stem of said anode, said heat-absorber 18 having alarge external head supplied with a handle 20 which is separated from the main body of the head by heat-insulating members 21in order to prevent the handle 20from becoming excessively heated. V

Extending from and about the tank 10 are parallel radiating fins 22, such fins being common to oil-immersed X-ray units.

shown in Figure 1. This is connected to a main switch 24: which in turn opens and closes the electrical circuit to an auto-transformer 25 having an adjustable tap 26 for regulating the voltage across the primary of a high tension transformer, later to be mentioned.

Resistance in serieswith the primary of a filament transformer for regulating the voltage across the primary of such filament trans- V former is indicated 27.

The primary of the above referred to high tension transformer is designated 28, and its secondary 29, while the primary of the filament transformer mentioned is 30, its secondary being designated 31.

Between the secondary 29 and the tank 10 there is a ground connection 32, and there is also a connection 33 between the secondary 29 and the secondary 31. The conduits to the filament of the X-ray tube 12 are designated of course providing electrical connection for the high tension current impressed upon said tube 12, the tank 10 high tension current.

In its regular operation, the tube 12 per- Such anode is designated 13 and has a threaded outer end, while the cathode of 7 absorption capacity,

which has become trically connected to the tank lOwhich forms a conductor or part of the circuit to one end of the secondary 29 of the high tension transformer, the other end of the secondary of saidtransformer, as previously indicated, being connected to agency of one of the conduits 3 1 from one end of the secondary of the filament transformer. The circuit is otherwise conventional.

. Examinationof Figure 2 will disclose. the stud 16 comprising a part of the casing 10. and to which'the anode 13 of the tube 12 is adapted to be secured.

Intermediate the wall of the tank 10 and the end of the anode is a washer 35 adapted to facilitate the sealing of the aperture intermediate the tube 12 and the casing. 10, and also making provision for the necessary rotation of the tube 12 until the target thereof is properly disposed to project X-light through the window in the cover 11 of the casing.

The hollow portion 17 of the anode 13 extends into close proximity to the tungsten button 36 upon the anode 13, suchbutton being very clearly shown in the cross sections of both Figures land 2.

The cooling member comprises a shank adapted to completely or substantially fill the hollow space 17, an enlargedthreaded portion adapted to be inserted into and be rotated into position in the socket 18 of the tank, a head, and a handle insulated from such head.

The reason head shown is to give to the removable section 19 of the anode 13 a greater heatit being obvious that the metal of the removable section 19'0f the anode should be integral and of a metal of great capacity with respect to heat-absorption.

During the operation of the tube 12 and without disconnecting the electrical connections which supply energy thereto, it is pos-' sible to remove one of the cooling members 19 heated and to substitute therefor a second member 19 which has been pre-cooled. By using a plurality of such members 19, and keeping the members to be inserted at a low temperature before insertion, it is possible to operate a tube 12 almost continuously without any danger of overheating. The advantages of such a structure over a water-cooled or mercury-cooled sys 'tem reside in the proposition that there are no external pipes to be installed, that there is no great weight attached to the cooling system, and that the present apparatus is particularly adapted to be used in a portable the-cathode through the outfit where mercury cooling or water-cool ing probably would be impracticable. A half dozen of such cooling ,instrumentalities 19 would be all that is required except under the most extraordinary circumstances; in fact, a

half dozen removable sections 19 for the anode 13 would probably sufiice for each and every emergency to which the tube in service may be subjected.

I claim:

1. An X-ray apparatus comprising an X-ray tube having a threaded section, a tank disposed about said tube and having a threaded lug to engage the threaded portion 15 of said tube, and a cooling element comprising a part of the anode of said tube and adapted to be removed from said tube through the walls of said tank.

2. In an X-ray system, a casing of relatively large capacity for heat absorption, an X-ray tube in said casing, an anode in said tube, means for energizing said tube and, heating said anode, means projecting from said anode through said casing for conducting the heat of said anode to said casing, and means associated with said casing for dissipating such conducted'heat by radiation.

JAMES S. THELEN. 

